At 40 and 45 nm process nodes, power has become the primary factor for FPGA selection. Spartan®-6 and Virtex®-6 FPGAs offer lower power, simpler power systems and PCB complexity, better reliability, and lower system cost. This white paper details how Xilinx designed for this new reality in Spartan-6 (45 nm) and Virtex-6 (40 nm) FPGA families, achieving dramatic power reductions over previous generation devices.